1. Field of the Invention
The present invention relates to a polyarylene sulfide resin composition for optical telecommunication members. Precisely, it relates to a polyarylene sulfide resin composition favorable to optical telecommunication members such as fiber-optics connector ferrules, sleeves, etc.
2. Description of the Related Art
As having the advantages of good dimensional accuracy, mechanical strength and heat resistance, silica-containing epoxy resin compositions have heretofore been widely used for optical telecommunication members such as fiber-optics connector ferrules, sleeves and others in the field of optical telecommunication.
However, the epoxy resin compositions require long molding cycles, and mold units used for them must be cleaned out for every batch. Therefore, mass production of the resin moldings is limited. What is more, recycling sprue, runners and others for them is impossible, and the yield of the materials for them is low. Thus, they have various problems peculiar to thermosetting resins.
Substitutable for them, thermoplastic resin compositions such as those of polyarylene sulfide (PAS) resins have been proposed. For example, in Japanese Patent Laid-Open No. 196208/1982, proposed is a PAS resin composition containing a spherical filler; and in Japanese Patent Laid-Open No. 299072/1994, proposed is a PAS resin composition containing silica, in which the filler, silica is subjected to surface treatment with a silane coupling agent. In International Patent Laid-Open No. WO95/25770, proposed is a PAS resin composition containing whiskers and spherical silica.
However, the resin compositions proposed are still unsatisfactory with respect to dimensional accuracy, and their applications to single-mode fiber-optics connector members and others that require especially high dimensional accuracy are limited.
In that situation, the present invention is to provide a PAS resin composition having the advantage of extremely high dimensional accuracy and therefore favorable to fiber-optics connector members, etc.
We, the present inventors have assiduously studied PAS resin compositions for optical telecommunication members, while paying special attention to their dimensional accuracy, and, as a result, have found that the crystallization profile of PAS and its resin compositions has a great influence on the dimensional accuracy of the resin moldings. On the basis of this finding, we have completed the present invention.
Specifically, the invention provides the following:
1. A polyarylene sulfide resin composition for optical telecommunication members, which comprises (A) from 20 to 35% by weight of a polyarylene sulfide having a crystallization temperature, as measured through differential scanning calorimetry, of not lower than 250xc2x0 C., and (B) from 65 to 80% by weight of silica.
2. A polyarylene sulfide resin composition for optical telecommunication members, which comprises (Axe2x80x2) from 20 to 35% by weight of a polyarylene sulfide, and (Bxe2x80x2) from 65 to 80% by weight of silica, and which has a crystallization temperature, as measured through differential scanning calorimetry, of not lower than 250xc2x0 C.
3. The polyarylene sulfide resin composition for optical telecommunication members of above 1 or 2, wherein the silica is a spherical silica having a mean particle size of from 1 to 10 xcexcm.